diff --git a/CHANGELOG.md b/CHANGELOG.md
index 73282e3..24370ab 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,8 +1,9 @@
 # Changelog
 
-## [2.1.0]
-- added script 'GeneratePseudonymKey.groovy' to compute pseudonyms
+## [2.1.0] - unreleased
+- added script `GeneratePseudonymKey.groovy` to compute pseudonyms
 - added script `Pseudonymize.groovy` to pseudonymize tokens (and lemmas)
+- added script `FilterKeys.groovy` to filter pseudonymization keys to contain actually used tokens/lemmas only
 
 ## [2.0] - 2021-10-07
 - for `.*\\.(freq|tsv)(\\.gz)?` input files automatically cumulate frequencies